costello



(No Model.) 2 Sheets-Sheet 1. T. H. COSTELLO.

LATHE UHUGK.

No. 259,291. Patented June 13, 1882,

UNITED STATES PATENT OFFICE.

THOMAS H. COSTELLO, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO H. H. GROSS, OF SAME PLACE.

LATHE-CHUCK.

SPECIFICATION forming part of Letters Patent No. 259,291, dated June 13, 1882,

Application filed February 27, 1882. (No model.)

To all whom it may concern Be it known that I, THOMAS H. OosrELLo, of the city of Chicago, county of Cook, and State of Illinois, have invented certain Improvements in Lathe-Chucks, of which the following is a specification.

The object of my invention is to provide a lathe-chuck with convenient, simple, and effective devices to render it universal, independent, and eccentric in its action and I have accom plished that object by the mechanical means hereinafter fully described with reference to the accompanying drawings, in which- Figure 1 represents a front view of a chuck having my improvement; Fig. 2, a back view of the same; Fig. 3, an interior view of the face portion; Fig. 4, a like view of the rear portion; Fig. 5, a detail view ofone side of the ring 0'; Fig. 6, an interior view of the back portion with ring G and the circular rack O removed therefrom in order to display the rounded elevations (3 upon the bottom of the circular groove in that part of the chuck; Fig. 7, a cross-section of the two parts and the inclosed devices together in proper position, taken as indicated by the broken line 7 7 in Fig. 6; Figs. 8, 9, 10, and 11, detail views of certain parts.

A indicates the front part of the case or shell of the chuck, and B the rear part. These parts are attached together by screw-bolts in the usual manner, and form a frame for the operative parts. a a a are the jaws, which are moved outward and inward in regard to the center by the turning of their screws a? a a which may be turned by means of a key or wrench applied to their outer square ends, a a a. Inside the case these screws are provided with pinions a a a", which gear with the circular rack O, which is adapted to move in its circular groove in part B, so that when one pinion is turned the circular rack (3 will impart the same movement to the other two.

0 is a ring fitting in the same groove and underlying the circular rack, as shown in Fig. 7. The under side of the ring 0 is provided with three depressions or sockets, e, as shown in Figs. 5 and 10, to correspond with and fit over the three elevations 0 upon the bottom of the circular groove in part B, which projections are shown in Fig. 6. The result of this construction is that when the ring 0 is in position, with its depressions 6 immediately over projections C the ring will rest solidly upon the bottom of its groove, and the circular rack (J, resting upon it, will be out of gear with the pinions a so that any one of such pinions may be operated independently of the other two; but when ring O is moved around so that the plain portion of it shall rest on the projections the ring and circular rack will be raised or moved in the direction of the pinions a and mesh with them.

It is obvious that when the circular rack is out of gear with the pinions a the jaws may, by the turning of the screws 0., be made to hold the work at theexact center or at any required distance from it.

My special device for moving the ring G in and out consists of the three cam-slots bin inner side of the flange of the part B and the pins 0 c c on the outer edge of ring 0'. These slots are shown in Fig. 9, which represents a segment of part B. They correspond in position to the pins 0 on the ring 0, and these pins have to be passed through theinner ends of these slots when the ring is put into the circular bed in the groove in part B, and the motion is imparted by the shaft 12, having its bearing in the case B, as shown in Fig. 11, and provided on its inner end with cam-wheel h and eccentric pin h, which works in slot 0 in the ring 0', and the lever H and its pin d on the outside of the case. The throw of the cam It will cause the outer end of lever H to describe the arc of a circle between t e holes 1" and r in the case, and in order to l tch the lever H in position at either one endof the are or the other it is made thin enough to spring a little, and is provided with the pointed pin 4*, which, upon reaching either hole, sinks into it and holds the lever with sufficient force to prevent accidental displacement, and thus the ring-gear O is held either in gear or out of gear with the pinion a as required. The circular rack 0 presents a smooth face to the ring 0, and might therefore revolve by its own momentum after the chuck ceases to revolve, or when it was designed not to be in gear with pinions a it might be thrown against the pinions unless some device were used to hold it in proper position. I have therefore invented such a device as is required and it consists of a tooth, l, which is provided with a base which moves in and out in a suitable groove in the flange of part B, as fully shown in Fig.8. That tooth has a beveled form to correspond with the intervals between the teeth or cogs of circular rack O, and has a threaded hole in its outer side, and into this hole is turned the headed pin L, threaded on its inner end to correspond with said hole, through a slot in the side of the case, so that when the pin is in position, with its point turned into the base of the tooth, by means of it the tooth may be forced down between two teeth of the circular rack and hold the latter against both circular motion and inward and outward motion and in order to hold the pin L to any desired adjustment in its slot it is provided with a spring-disk, through the center of which it enters from the outer side, which is the con- Vexed side, the periphery of the disk being against the side of the case. In screwing the pin into the base of the tooth the disk is compressed and acts as a spring, and thus the pin is held to its adjustment in its slot in the case.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The combination of the ring 0, having the series of pins 0 upon its outer periphery, and the series of cam-slots b in part B as cooperating devices in the operation of forcing the circular rack G into and out of gear with pinions a substantially as described.

2. The lever H, having pin 7* and operating upon shaft 1;, in combination with plate or part B, having holes 4* r, substantially as described.

3. The combination of the headed pin L and its spring-disk in position over its slot in the flange of part B, and the tooth 1, adapted to latch circular rack G in any position required or to unlatch the same at will, substantially as described.

THOMAS H. COSTELLO. Witnesses:

J NO. V. HAIR, J. G. HURZOGH. 

